1. Field of the Invention
The invention relates to an internal combustion engine, and more specifically to a rotary internal combustion engine.
2. Technical Background
The internal combustion engine has been at the center of industrial evolution for the last century. One of the most dramatic aspects of this evolution has been the automobile, which has helped to shape and transform a culture. Yet for all the dramatic technological progress over the last 100 years, the internal combustion engine, and particularly the reciprocating internal combustion engine, has not substantially changed during that period. Although significant improvements have been made in the design and construction of internal combustion engines, the reciprocating piston internal combustion engine that dominates the automotive industry remains notoriously energy inefficient, commanding only about a 24% overall efficiency.
Rotary engines overcome some of the problems inherent in reciprocating internal combustion engines. The Wankel rotary engine is the most well-known of the rotary engines, having enjoyed a small amount of commercial success in certain automobiles. The engine has approximately 48% fewer moving parts than an equivalent reciprocating piston engine, with about one third the size and weight. One advantage of the Wankel rotary engine over reciprocating piston internal combustion engines is a higher RPM than reciprocating piston engines since the reciprocating motion of the pistons is eliminated. However, the Wankel engine also tends to have low torque at high speeds, thereby resulting in increased fuel consumption.
Prior art rotary engines have attempted to address many of the shortcomings of both the reciprocating piston internal combustion engine and the Wankel rotary engine. Prior art rotary engines have, for example, used a rotating valve which compression region of the engine and the rotating combustion chamber as the piston advances toward the valve in order to minimizes sharp pressure changes in the engine. However, such prior art rotary engines fail to provide for a continuous discharge of the expanding combustion gases from the combustion chamber as the valve and combustion chamber rotate. Other prior art rotary engines disclose rotating valves having internal combustion chambers, and include passages for equalizing pressure between the annular region surrounding the main rotor and the combustion chamber. However, the passage within these rotary engines are narrowly constructed, and provide a limited opportunity to deliver combustion gases to the annular region.